Crystal structure of diaquabis(3-amino-1,2,4-triazole-5-carboxylato)- cadmium(II), Cd(H2O)2(C3H3N4O2)2

Abstract

C 6 H 10 CdN 8 O 6 ,monoclinic, P12 1 /c1(no. 14), a =9.456(4) Å, b =9.492(4) Å, c =6. Source of materialThe title compound was synthesized by the solvent evaporation method. 3-Amino-1,2,4-triazole-5-carboxylic acid (HL, 0.0128 g, 0.1 mmol) was dissolved in aN aOH solution (1.0 mol/L, 1.0 ml). The mixture was diluted by 10 ml distilled water and 10 ml EtOH, and the pH value was adjusted to 4.0 with HCl solution (1.0 mol/L). Cd(Ac) 2 · 2H2O(0.0532 g, 0.2 mmol) was dissolved in distilled water (5.0 ml) and then added to the above mixed solution.The reaction mixture was filtered and the filtrate was left undisturbedly at room temperature. The colorless crystals were obtained after two weeks. Experimental detailsAll Hatoms were positioned geometrically and allowed to ride on their parent atoms at distances of d(Csp 2 -H) =0 .93 Å with U iso(H) =1.2 Ueq(parent atom), d(N-H) =0.86 Å with Uiso(H) = 1.2 U eq (parent atom) and d(O-H) =0 .85 Å with U iso (H) = 1.5 U eq (parent atom).

Multidimensional Transition Metal Complexes Based on 3-Amino-1H-1,2,4-triazole-5-carboxylic Acid: From Discrete Mononuclear Complexes to Layered Materials

“…Bond-valence-sum (BVS) calculations gives a value of 2.02 for Mn1, indicating that Mn1 has the +2 oxidation state (command Calc Coord in PLATON [49]). This compound is isotypical to the already described compound [Cd(Hatrc) 2 (H 2 O) 2 ]·2H 2 O [34].…”

“…The Hatrc − residue adopts a typical N , O -bidentate chelating mode (Scheme 1, type I) with the Zn–O and Zn–N found within the expected ranges (Table 1). Considering compounds 1 , 2 and the isotypical [Cd(Hatrc) 2 (H 2 O) 2 ]·2H 2 O [34], the distances between the metal centers and the atoms in the first coordination sphere follow the tendency of the ionic radius Zn 2+ < Mn 2+ < Cd 2+ . Conversely, the O–M–N bite angles subtended by the Hatrc − residue follow, as expected, the opposite tendency (Table 1).…”

“…A meticulous survey in the literature and in Cambridge Structural Database (CSD, Version 5.36 updated November 2014) [33] revealed the existence of only five structures with residues of H 2 atrc (this molecule being the sole organic ligand). Two of these known compounds comprise discrete complexes ([Cd(Hatrc) 2 (H 2 O) 2 ] [34] and (NH 4 ) 2 [Cd(Hatrc) 4 ] [35]), whereas the other two are isotypical 3D MOFs ([M(Hatrc) 2 (H 2 O)] n ; M 2+ = Sr 2+ or Ba 2+ ) [36]. The remaining compound is an interesting tubular structure formed by the crystal packing of [Cu(atrc)(H 2 O)] complex units, whose channels have an internal diameter of ca.…”